Ovarian carcinomas in hens will be studied to find causal factors and develop diagnostic tests for presence of tumors. Estrogen, progesterone, and testosterone plasma levels of tumorous hens resemble those of non-ovulating hens with the exception of one estrogenic tumor type. The cyclic nature of tumor incidence will allow a further analysis of: (a) hormonal levels; (b) T-cell function; (c) sites of initial tumor development; (d) morphopathogenesis of tumors; and (e) steroid receptor levels in tumors as well as oviductal tissue. In addition, biopsied hens will be staged as to tumor development and multiple blood samples taken. Some biopsied hens will be implanted with estrogen or progesterone to see what effect the hormones have on tumor development. Lymphocytes from either peripheral blood or splenic suspensions will be tested for PHA reactivity and reactivity to a tumor associated antigen detected through use of heterologous antiserum raised against purified tumor extracts. Presence of this tumor-associated antigen will be evaluated in the plasma of hens with tumors at various stages of development. In order to interpret the hormonal data, it is necessary to know if the generally bulky tumor growth will alter levels through presence of steroid receptors. These will be measured along with receptors in oviductal tissue. Further efforts will be made to develop cell lines from tumor tissue and to use such lines to find out if tumor cells are steroidogenic or responsive to gonadotropic hormones.